The present invention relates to magnetic data recording, and more particularly, to perpendicular magnetic data recording.
Perpendicular recording has been used to achieve higher recording densities. The National Storage Industry Consortium (SIC) believes that perpendicular recording will become necessary to achieve the densities above 100 Gbit/in2.
Writes for a perpendicular medium with a soft underlayer occur at a trailing (or downstream) edge of the write element. The curvature of the transitions is due to the rectangular shape of the trailing edge of the write element. Also, resolution loss between a write pole tip and the magnetic medium due to a physical spacing between them and saturation of corners of the write element can cause the curvature of the transitions. As widths of write tracks decrease, the resolution loss and the saturation of corners of the write element become larger contributors to the curvature.
As track density increases, edges of the track become a large part of the overall track width. The track edges are characterized by noise and imperfectly written transitions, in particular, the transitions with curvature across the track. Thus, it is important to match a read impulse shape, which is a line, with a written transition shape.